Upgrading old PC just enough

[Alexventura]

PC: HP Compaq 6000 Pro NV503UT SFF (Small Form Factor)
CPU: Core 2 Quad Q9400@2.6GHz
Ram: 4GB (2x2gb Dual Channel)
HDD: 250gb
WiFi: PCI Rosewill RNX-N300X 802.11b/g,n Draft
PSU: 240w
GPU: MSI GeForce GTX 460 (Fermi) N460GTX CYCLONE 1gb

Upgrades (used but only $35):
GPU: MSI GeForce GTX 460 (Fermi) N460GTX CYCLONE 1GB
PSU: 550w LOGISYS Computer PS550E12 ATX12V

I want to upgrade to a gtx460 but the PCIe x16 is low profile!
So I want to use a PCIe ribbon cable or whatever it's called(I think some people use them to mount the gpu to the case?) to just leave it with the covers open on top, Will it work at all with the mobo? Since I keep hearing about proprietary blah blah..Will it affect performance with a ribbon cable?

2nd question is if I get the 550w psu, will it fit in the Small Form Factor case? If not I'm OK if I leave it out like the gtx460 but is the PSU compatible with the system? Say...the cables, if I decide to remove the old 230w?

Last question is if the 550w psu mentioned is enough for the system and gtx460?

NOTE: I don't want to spend more for an old PC or even build one from scratch or whatever! I'm fine with the PSU & GPU outside with the case open! The question is if it works at all since I don't know much about Small Form Factor PC and How far proprietary goes. Thanks!

 

[CBender]

Your best chance is to buy a really cheap second hand normal tower case that would fit the system. By having components out in the open you are taking a very big risk. The gpu might short circuit where the psu could even catch fire (spillage or different).

I WOULD DEFINITELY ADVISE AGAINST THAT.

As for the ribbon (pci-e riser) if it is of a good quality you wouldn't see any noticeable performance difference. If you don't have it already it better to invest into a different case instead of the riser.

For the power supply goes the same as above. Buy a normal tower case second hand and buy a normal power supply. I doubt that the power supply fits the case and as I said psu out of the case is a major hazard. Especially if it is of a poor quality like this one.

 

[ScrewySqrl]

why not get a half-height 750ti? faster than the 460, uses less power and better all around

edit: oh, and get rid of that psu-shaped explosive device from Logisys.